Aug. 8, 2012 -- When The New York Times reported Tuesday that doctors at HCA Health Care hospitals in Florida might have performed cardiac procedures on patients who didn't need them, it raised questions about the risks of such unnecessary surgery.
ABCNews.com's Medical Unit breaks down the risks of such procedures for you, step by step:
Since cardiac catheterization is a diagnostic test, doctors tend to disagree about when it is necessary to subject patients to it. As such, this area is a bit more "gray" than unnecessary stents, doctors told ABCNews.com.
"If you have a massive heart attack, almost everyone would agree you should undergo cardiac catheterization," Dr. Deepak Bhatt, who directs the Integrated Interventional Cardiovascular Program at Brigham and Women's Hospital in Boston, told ABCNews.com. "That's one end of the spectrum where really there's little room for debate."
On the other end, there are symptom-free patients who perhaps have abnormal stress-test results. Or maybe they're having chest pains in the emergency room but are only experiencing indigestion. Either way, they're told they need the test.
"How does a patient, when they're having a heart attack, say, 'I don't think so?'" Dr. Mark Adelman, the chief of Vascular Surgery at NYU Langone Medical Center, asked ABCNews.com.
When a patient undergoes cardiac catheterization, a wire tube, or sheath, is inserted into the arteries in the patient's groin or wrist area (femoral or radial arteries). The sheath carries equipment up to the heart, but before it can get there, the patient faces an initial set of risks:
Bleeding from the artery in the groin or wrist
Blood clot in the arm or leg, which could cause the patient to lose a limb
Bleeding into the belly (if the artery near the groin is punctured too high)
"Any of those can be life-threatening problems," Adelman told ABCNews.com. "Those are the local complications."
Next, the doctors thread the sheath up the artery toward the heart, resulting in the second set of risks:
Sheath disrupts plaque in the arteries, causing a clot
Equipment punctures artery walls
Once doctors have threaded their equipment inside the body, they can choose whether to insert a stent, which is a metal mesh tube that works with a balloon to expand and open up a narrow artery. If a stent is inserted, the patient faces another set of immediate risks:
Equipment disrupts plaque in coronary artery, clogging a blood vessel and blocking oxygen from the heart
Stent punctures coronary artery
Regardless of whether a stent is necessary, Bhatt said one or two out of every 100 patients undergoing stent surgery experiences major complications, such as heart attack or stroke, even death. He said the risk is higher in people who have heart disease, but even for patients who don't need stents, the risk isn't "zero."
Bhatt said there's less than a 1 percent chance a patient would experience complications from plaque breaking off and traveling downstream in the same artery to cause a heart attack.
Once patients makes it through stent surgery, they also face long-term risks as the body reacts to the foreign object.
Stents can develop blood clot
Stents accumulate scar tissue over a period of months
The blood clot risk is rare at this stage, however, occurring less than 1 percent of the time, Bhatt said.
"When it does happen, it can result in a heart attack," he said. "One minute the stent is open, and in less than a minute, it's closed."
Less than 10 percent of patients now develop scar tissue in stents -- before 2003, when stent technology was less developed, the risk was greater.
What's the Takeaway?
Although invasive heart procedures can be lifesaving and worth the risk for patients who have heart disease, patients who don't need cardiac catheterization or stents are exposed to unnecessary risks before and after surgery.
"You're worse off than you would have otherwise been," Bhatt said, adding that he didn't believe there was an "epidemic" of unnecessary heart procedures.
Adelman said it's one thing to order unnecessary blood work or brain imaging tests, but dangerous to order unnecessary invasive procedures.
"Ordering an unnecessary MRI is very expensive and wasteful, but it doesn't hurt anybody," he said. But unneeded cardiac procedures can cause strokes, heart attacks and death. "We're willing to accept those risks when it's necessary. ... When it's medically unnecessary, it's not only expensive, but it's terrible malpractice."